我想使用boost intercess共享对象的向量。对象来自以下结构：
struct Foo
{
int id;
float time;
bool isFoo;
float myArray[7];
std::vector<int> vectorData;
};
我正在创建Boost Inter Process分配器和间处理向量：
typedef allocator<Foo, managed_shared_memory::segment_manager> FooAllocator;
typedef std::vector<Foo, FooAllocator> FooVector;
在我的主函数中，我基于：
初始化内存段，分配器和向量Boost->在共享内存中创建向量
so：
managed_shared_memory mem_segment(open_or_create, "MemShare", 65536);
const FooAllocator alloc_inst(mem_segment.get_segment_manager());
fooVector = mem_segment.find_or_construct<FooVector>("FooVector")(alloc_inst);
现在，这适用于FOO结构中的每个数据类型，除了向量。因此，如果我尝试分享这一点，我会从FOO中获得所有成员，对于向量数据，我将获得"未定义的内存位置"我知道不能直接共享std :: vector。因此，我使用boost ::我创建了新的foo结构：
struct FooInter
{
int id;
float time;
bool isFoo;
float myArray[7];
MyVector* pointcloud;
};
myVector在哪里：
typedef allocator<int, managed_shared_memory::segment_manager> VectorAllocator;
typedef boost::interprocess::vector<int, VectorAllocator> MyVector;
我正在为MyVector分配内存，
const VectorAllocator vec_alloc_inst(mem_segment.get_segment_manager());
MyVector* tmpVec = mem_segment.construct<MyVector>("MyVector")(vec_alloc_inst);
那么我现在尝试做的就是将foo映射到foointer。我正在将矢量数据映射到循环中：
for (int t = 0; t < foo.vectorData.size()-1; t++) {
tmpVec->push_back(foo.vectorData[t]);
}
然后将TMPVEC复制到foointer.vectordata：
memcpy(fooInter.pointcloud, tmpVec, sizeof(int) * tmpVec->size());
这有效，但不适合foo.vectordata的整体尺寸。因此，它适用于100个项目，但是如果我使用foo.vectordata.size((，它将返回不良内存salroc。
有人可以帮助我。我需要知道分享这种类型结构的正确方法。我觉得我正在做的事情是完全错误的。也许我需要将向量序列化为字符串或类似的内容。
编辑：
基于sehe的答案：
我有类型的对象msg：
struct Foo
{
int id;
float time;
bool isFoo;
float myArray[7];
std::vector<int> pointcloud;
};
我需要在Inter_foos中传递该对象。因此，在SEHE的代码中：
int main() {
auto segment = Shared::open();
auto& inter_foos = *segment.find_or_construct<InterFoos>("InterFoos")(segment.get_segment_manager());
// you can directly append to the shared memory vector
int nextid = inter_foos.size();
//instead of this
inter_foos.push_back({++nextid, 0, true, {.1,.2,.3,.4,.5,.6,.7}, Ints ({10,20,30}, segment.get_segment_manager()) });
//i need this
inter_foos.push_back({msg.id, msg.time, true, msg.myArray, Ints (msg.pointcloud, segment.get_segment_manager()) });
//i can't pass msg.poincloud to this object!!!
// or copy from a non-shared vector:
std::vector<Foo> const local {
{++nextid, 0, true, {.1,.2,.3,.4,.5,.6,.7}, {10,20,30} },
{++nextid, 1, true, {.2,.3,.4,.5,.6,.7,.8}, {20,30,40} },
{++nextid, 2, true, {.3,.4,.5,.6,.7,.8,.9}, {30,40,50} },
};
for (auto& local_foo : local)
inter_foos.emplace_back(local_foo);
// print the current contents
for (auto& foo : inter_foos)
std::cout << foo << "n";
}
您可以使用
的方法- 制作boost的非共享副本::概要共享内存对象
- boost :: Intercess scoped_allocator和不共享内存中的容器的容器
请参阅此演示
活在coliru
#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <boost/interprocess/containers/vector.hpp>
#include <boost/container/scoped_allocator.hpp>
#include <iostream>
#include <vector>
namespace Shared {
namespace bip = boost::interprocess;
namespace bc = boost::container;
using Segment = bip::managed_shared_memory;
using Manager = Segment::segment_manager;
template <typename T> using Alloc = bc::scoped_allocator_adaptor<bip::allocator<T, Manager> >;
template <typename T> using Vector= bip::vector<T, Alloc<T> >;
Segment open() { return { bip::open_or_create, "MySharedMemory", 10ul<<20 }; }
template <typename Alloc = Alloc<void> >
struct Foo {
using allocator_type = typename Alloc::template rebind<Foo>::other;
using Ints = bip::vector<int, typename Alloc::template rebind<int>::other>;
Foo(int id, float time, bool isFoo = false, std::initializer_list<float> floats = {}, Ints data = {})
: id(id), time(time), isFoo(isFoo), vectorData(std::move(data))
{
std::copy_n(floats.begin(), std::min(floats.size(), 7ul), myArray);
}
template <typename OA, typename A>
Foo(Foo<OA> const& other, A alloc = {})
: id(other.id), time(other.time), isFoo(other.isFoo),
vectorData(other.vectorData.begin(), other.vectorData.end(), alloc)
{
std::copy(std::begin(other.myArray), std::end(other.myArray), myArray);
}
int id;
float time;
bool isFoo;
float myArray[7] = {};
Ints vectorData;
};
template <typename A>
std::ostream& operator<<(std::ostream& os, Foo<A> const& f) {
os << "{"
<< f.id << ", "
<< std::fixed << f.time << ", "
<< std::boolalpha << f.isFoo << ", "
<< "[";
std::copy(std::begin(f.myArray), std::end(f.myArray), std::ostream_iterator<float>(std::cout, ";"));
os << "], [";
std::copy(std::begin(f.vectorData), std::end(f.vectorData), std::ostream_iterator<int>(std::cout, ";"));
return os << "] }";
}
}
using Foo = Shared::Foo<std::allocator<void> >;
using InterFoo = Shared::Foo<>;
using InterFoos = Shared::Vector<InterFoo>;
using Ints = Shared::Vector<int>;
int main() {
auto segment = Shared::open();
auto& inter_foos = *segment.find_or_construct<InterFoos>("InterFoos")(segment.get_segment_manager());
// you can directly append to the shared memory vector
int nextid = inter_foos.size();
inter_foos.push_back({++nextid, 0, true, {.1,.2,.3,.4,.5,.6,.7}, Ints ({10,20,30}, segment.get_segment_manager()) });
// or copy from a non-shared vector:
std::vector<Foo> const local {
{++nextid, 0, true, {.1,.2,.3,.4,.5,.6,.7}, {10,20,30} },
{++nextid, 1, true, {.2,.3,.4,.5,.6,.7,.8}, {20,30,40} },
{++nextid, 2, true, {.3,.4,.5,.6,.7,.8,.9}, {30,40,50} },
};
for (auto& local_foo : local)
inter_foos.emplace_back(local_foo);
// print the current contents
for (auto& foo : inter_foos)
std::cout << foo << "n";
}
打印：
{1, 0.000000, true, [0.100000;0.200000;0.300000;0.400000;0.500000;0.600000;0.700000;], [10;20;30;] }
{2, 0.000000, true, [0.100000;0.200000;0.300000;0.400000;0.500000;0.600000;0.700000;], [10;20;30;] }
{3, 1.000000, true, [0.200000;0.300000;0.400000;0.500000;0.600000;0.700000;0.800000;], [20;30;40;] }
{4, 2.000000, true, [0.300000;0.400000;0.500000;0.600000;0.700000;0.800000;0.900000;], [30;40;50;] }
第二次运行：
{1, 0.000000, true, [0.100000;0.200000;0.300000;0.400000;0.500000;0.600000;0.700000;], [10;20;30;] }
{2, 0.000000, true, [0.100000;0.200000;0.300000;0.400000;0.500000;0.600000;0.700000;], [10;20;30;] }
{3, 1.000000, true, [0.200000;0.300000;0.400000;0.500000;0.600000;0.700000;0.800000;], [20;30;40;] }
{4, 2.000000, true, [0.300000;0.400000;0.500000;0.600000;0.700000;0.800000;0.900000;], [30;40;50;] }
{5, 0.000000, true, [0.100000;0.200000;0.300000;0.400000;0.500000;0.600000;0.700000;], [10;20;30;] }
{6, 0.000000, true, [0.100000;0.200000;0.300000;0.400000;0.500000;0.600000;0.700000;], [10;20;30;] }
{7, 1.000000, true, [0.200000;0.300000;0.400000;0.500000;0.600000;0.700000;0.800000;], [20;30;40;] }
{8, 2.000000, true, [0.300000;0.400000;0.500000;0.600000;0.700000;0.800000;0.900000;], [30;40;50;] }
范围分配器
请注意：
for (auto& local_foo : local)
inter_foos.emplace_back(local_foo);
由于范围的范围分配器而受支持并通过Boost的容器实现来支持和传递。如果您不使用它，则看起来像这样： Live on Coliru
template <typename T> using Alloc = bip::allocator<T, Manager>;
// ...
for (auto& local_foo : local)
inter_foos.emplace_back(local_foo, segment.get_segment_manager());
¹使用映射文件，因为在Coliru上不支持共享内存
我无法想象使用memcpy复制MyVector的工作状况很好。当然您需要的是：
void FooInter::setVector(const std::vector<int>& vec) {
const VectorAllocator vec_alloc_inst(mem_segment.get_segment_manager());
const auto tmp = mem_segment.construct<MyVector>("MyVector")(vec_alloc_inst);
tmp->insert(tmp->begin(), vec.begin(), vec.end());
pointcloud = tmp;
}
换句话说，构造由pointcloud指向的对象，然后插入其中。